Tintagel Castle is located in Cornwall, UK near to Tintagel. It was built by Reginald, Earl of Cornwall on Tintagel Head, where according to Cornish legends the ancient Kings of Cornwall held their court. The castle was built for propaganda purposes, and had no real strategic value. It is often claimed that the Castle at Tintagel Head was the birthplace of King Arthur, since traditional accounts say he was raised by the King of Cornwall. A Dark Ages Celtic fortress did exist there, however, and in 1998 a so-called "Arthur stone" was discovered there that could provide some basis for the legend.

The present-day ruins of the castle are situated on a rocky headland that overlooks the Cornish coast.

The modern day village of Tintagel was known as Trevena until the 1850s, when the Victorians renamed it to promote tourism on the back of the King Arthur and Camelot legends. Strictly speaking, Tintagel is just the name of the headland.